ID   P2XB_DICDI              Reviewed;         369 AA.
AC   Q553Y1;
DT   15-DEC-2009, integrated into UniProtKB/Swiss-Prot.
DT   18-MAR-2008, sequence version 2.
DT   25-MAY-2022, entry version 90.
DE   RecName: Full=P2X receptor B;
DE            Short=P2XB;
GN   Name=p2xB; ORFNames=DDB_G0275293;
OS   Dictyostelium discoideum (Slime mold).
OC   Eukaryota; Amoebozoa; Evosea; Eumycetozoa; Dictyostelia; Dictyosteliales;
OC   Dictyosteliaceae; Dictyostelium.
OX   NCBI_TaxID=44689;
RN   [1]
RP   NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA].
RC   STRAIN=AX4;
RX   PubMed=12097910; DOI=10.1038/nature00847;
RA   Gloeckner G., Eichinger L., Szafranski K., Pachebat J.A., Bankier A.T.,
RA   Dear P.H., Lehmann R., Baumgart C., Parra G., Abril J.F., Guigo R.,
RA   Kumpf K., Tunggal B., Cox E.C., Quail M.A., Platzer M., Rosenthal A.,
RA   Noegel A.A.;
RT   "Sequence and analysis of chromosome 2 of Dictyostelium discoideum.";
RL   Nature 418:79-85(2002).
RN   [2]
RP   NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA].
RC   STRAIN=AX4;
RX   PubMed=15875012; DOI=10.1038/nature03481;
RA   Eichinger L., Pachebat J.A., Gloeckner G., Rajandream M.A., Sucgang R.,
RA   Berriman M., Song J., Olsen R., Szafranski K., Xu Q., Tunggal B.,
RA   Kummerfeld S., Madera M., Konfortov B.A., Rivero F., Bankier A.T.,
RA   Lehmann R., Hamlin N., Davies R., Gaudet P., Fey P., Pilcher K., Chen G.,
RA   Saunders D., Sodergren E.J., Davis P., Kerhornou A., Nie X., Hall N.,
RA   Anjard C., Hemphill L., Bason N., Farbrother P., Desany B., Just E.,
RA   Morio T., Rost R., Churcher C.M., Cooper J., Haydock S., van Driessche N.,
RA   Cronin A., Goodhead I., Muzny D.M., Mourier T., Pain A., Lu M., Harper D.,
RA   Lindsay R., Hauser H., James K.D., Quiles M., Madan Babu M., Saito T.,
RA   Buchrieser C., Wardroper A., Felder M., Thangavelu M., Johnson D.,
RA   Knights A., Loulseged H., Mungall K.L., Oliver K., Price C., Quail M.A.,
RA   Urushihara H., Hernandez J., Rabbinowitsch E., Steffen D., Sanders M.,
RA   Ma J., Kohara Y., Sharp S., Simmonds M.N., Spiegler S., Tivey A.,
RA   Sugano S., White B., Walker D., Woodward J.R., Winckler T., Tanaka Y.,
RA   Shaulsky G., Schleicher M., Weinstock G.M., Rosenthal A., Cox E.C.,
RA   Chisholm R.L., Gibbs R.A., Loomis W.F., Platzer M., Kay R.R.,
RA   Williams J.G., Dear P.H., Noegel A.A., Barrell B.G., Kuspa A.;
RT   "The genome of the social amoeba Dictyostelium discoideum.";
RL   Nature 435:43-57(2005).
RN   [3]
RP   FUNCTION, SUBCELLULAR LOCATION, AND DISRUPTION PHENOTYPE.
RX   PubMed=19833731; DOI=10.1074/jbc.m109.045674;
RA   Ludlow M.J., Durai L., Ennion S.J.;
RT   "Functional characterization of intracellular Dictyostelium discoideum P2X
RT   receptors.";
RL   J. Biol. Chem. 284:35227-35239(2009).
CC   -!- FUNCTION: P2X receptors are ATP-gated ion channels that play a role in
CC       intracellular calcium signaling. Not required for the purinergic
CC       response to extracellular nucleotides. Not essential for
CC       osmoregulation. Inward currents are evoked by intracellular ATP and ATP
CC       analogs. Insensitive to the P2 receptor antagonists PPADS and suramin,
CC       and also copper ions. Inhibited by sodium ions. Permeable to chloride
CC       ions. {ECO:0000269|PubMed:19833731}.
CC   -!- SUBCELLULAR LOCATION: Contractile vacuole membrane
CC       {ECO:0000269|PubMed:19833731}. Note=Ligand binding domain within the
CC       lumen of the vacuole.
CC   -!- DISRUPTION PHENOTYPE: Null cells are still capable of osmoregulation
CC       and do not show any noticeable differences in their sensitivity to
CC       hypotonic conditions. Quintuple p2xA/p2xB/p2XC/p2xd/p2xE null cells
CC       exhibit a slight delay in their osmoregulatory response, but are still
CC       capable of regulating their cell volume in water. Extracellular
CC       purinergic response to ATP persists in the quintuple null cells and
CC       p2xB null cells with no alteration in the kinetics of the response, but
CC       the magnitude of the response is lower. Responses to the calmodulin
CC       antagonist calmidazolium are reduced and intracellular calcium
CC       signaling is disrupted in quintuple null cells. The presence of copper
CC       prevents both wild type and quintuple null cells from undergoing an
CC       osmoregulatory decrease in cell volume. No obvious morphological
CC       phenotype was apparent in the p2xB or quintuple p2x null strains. The
CC       quintuple null strains grow slightly slower than wild type in shaking
CC       axenic cultures. {ECO:0000269|PubMed:19833731}.
CC   -!- SIMILARITY: Belongs to the P2X receptor family. {ECO:0000305}.
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DR   EMBL; AAFI02000013; EAL69927.2; -; Genomic_DNA.
DR   RefSeq; XP_643830.2; XM_638738.2.
DR   AlphaFoldDB; Q553Y1; -.
DR   PaxDb; Q553Y1; -.
DR   EnsemblProtists; EAL69927; EAL69927; DDB_G0275293.
DR   GeneID; 8619877; -.
DR   KEGG; ddi:DDB_G0275293; -.
DR   dictyBase; DDB_G0275293; p2xB.
DR   eggNOG; ENOG502RE1D; Eukaryota.
DR   HOGENOM; CLU_060033_0_0_1; -.
DR   InParanoid; Q553Y1; -.
DR   OMA; DINFNTH; -.
DR   PhylomeDB; Q553Y1; -.
DR   Reactome; R-DDI-139853; Elevation of cytosolic Ca2+ levels.
DR   Reactome; R-DDI-418346; Platelet homeostasis.
DR   Reactome; R-DDI-6798695; Neutrophil degranulation.
DR   Reactome; R-DDI-844456; The NLRP3 inflammasome.
DR   PRO; PR:Q553Y1; -.
DR   Proteomes; UP000002195; Chromosome 2.
DR   GO; GO:0031164; C:contractile vacuolar membrane; IDA:dictyBase.
DR   GO; GO:0016021; C:integral component of membrane; IEA:UniProtKB-KW.
DR   GO; GO:0005524; F:ATP binding; IC:dictyBase.
DR   GO; GO:0035381; F:ATP-gated ion channel activity; IDA:dictyBase.
DR   GO; GO:0140417; F:ATP-sensitive calcium-release channel activity; IGI:dictyBase.
DR   GO; GO:0070588; P:calcium ion transmembrane transport; IGI:dictyBase.
DR   GO; GO:0071476; P:cellular hypotonic response; IGI:dictyBase.
DR   GO; GO:0006811; P:ion transport; IDA:dictyBase.
DR   GO; GO:0050848; P:regulation of calcium-mediated signaling; IGI:dictyBase.
PE   3: Inferred from homology;
KW   Ion channel; Ion transport; Ligand-gated ion channel; Membrane; Receptor;
KW   Reference proteome; Transmembrane; Transmembrane helix; Transport; Vacuole.
FT   CHAIN           1..369
FT                   /note="P2X receptor B"
FT                   /id="PRO_0000390409"
FT   TOPO_DOM        1..25
FT                   /note="Cytoplasmic"
FT                   /evidence="ECO:0000255"
FT   TRANSMEM        26..46
FT                   /note="Helical"
FT                   /evidence="ECO:0000255"
FT   TOPO_DOM        47..369
FT                   /note="Lumenal"
FT                   /evidence="ECO:0000255"
FT   REGION          283..296
FT                   /note="Pore-forming motif"
FT                   /evidence="ECO:0000255"
SQ   SEQUENCE   369 AA;  41871 MW;  52C76B9970D4C483 CRC64;
     MTIDWDSILS YNTIKVVRIR DRRLGILHLC FLIVIVLYVV VYSAIIKKGY VTTEEPVGSI
     RTSLLAPDEL KSNQAYCKNN TEPYPYEKLD CVYYDEKLAL FPIGDDVGFT ASTRMRISDQ
     TVNCSLMNPS CKFYTNTSMN VYLADIESFT VLIDHTMYAP SSQIQFNGDD LSGYVLDQNG
     NEIQLNESVN TIGVQGKPDI LQLGKLLEFA GVDLDGPSLV NSSNSIRYDG CVLFVFIEYS
     NTFSYDLKKI KYVYSIKKVD DTAYDVPEVI ILNNENSRLY YKRHAIRLIF IQTGVIGSFN
     FQSLLLTLVS GLGLLTVSTL IVDQLAIRFL PQRKSYSSLK FQTTESFRMK KKIVNDDGED
     KLYHNIEAL